Acute Stent-Induced Endothelial Denudation: Biomechanical Predictors of Vascular Injury

Area of Science:

• Biomedical Engineering
• Cardiovascular Research
• Medical Device Design

Background:

• Concerns regarding local drug delivery and bioresorbable scaffold performance highlight the need to understand stent design's impact on arterial response.
• Optimizing stent design requires correlating drug release, arterial injury, and pharmacodynamics.

Purpose of the Study:

• To test the hypothesis that vascular injury is predictable from stent design.
• To investigate how stent deployment force and design influence arterial circumferential stress and injury.
• To examine the effect of stent strut thickness on arterial wall shear stress and stress distribution.

Main Methods:

• Numerical simulations and ex vivo experiments were conducted on three stent designs (slotted tube, corrugated ring, delta wing).
• Arterial injury resulting from device deployment was assessed.
• Computational models evaluated the impact of varying strut thickness on stress distributions.

Main Results:

• Predicted arterial circumferential stress exceeding 49.5 kPa correlated with observed ex vivo endothelial denudation across stent designs.
• Increased strut thickness was predicted to increase denuded areas and regions of low wall shear stress.
• Acute arterial injury post-stent expansion is linked to high circumferential hoop stresses in the interstrut region.

Conclusions:

• Acute arterial injury following stent expansion is primarily caused by high circumferential hoop stresses.
• Denuded area profiles are dependent on the geometric features of the stent's unit cell.
• Understanding these biomechanical interactions is crucial for optimizing drug-device interactions in local drug delivery.